This invention relates to a shoe making machine and more particularly to a device relating to the raising or gluing operation with respect to the marginal portion of the undersurface of a shoe body.
When a leather shoe is made, a raising operation as well as a gluing operation are required in order to properly affix the shoe body comprising an instep portion, a heel portion, and a tiptoe portion, i.e., the upper portion of a shoe to the bottom of a shoe, i.e., the lowest portion of a shoe. The raising operation is done on the marginal portion of the under-surface of the shoe body.
Now, in order to carry out said raising operation satisfactorily, firstly, the shoe body must be held or set properly; secondly, a shoe body setting equipment and a raising or gluing equipment must be controlled properly with respect to each other; thirdly, a shoe body must be determined promptly whether it is for the right or the left; and lastly, a consideration must be paid for the processing tool or the brush because it is easily deformed. Also, intimacy of the brush with respect to the surface to be processed or raised is very important.
A conventional shoe making machine, particularly the one relating to the shoe body setting equipment includes a stationary supporting member clamping and holding the heel portion of a shoe body; a movable tiptoe portion receiving member having its original position to return in a position slightly away from the tiptoe of a standard shoe body of the largest size; and a movable head having a raising brush or a gluing brush and having its original portion to return in a position slightly away from said receiving member, all being arranged on a stage.
In raising or gluing operation, the heel portion is clamped and held by the stationary supporting member first. Then, the tiptoe portion supporting member having a sensor such as a limit switch is moved to support the tiptoe of the shoe body, thereby setting the shoe body by means of said two members.
Thereafter the raising or gluing head is moved in order to carry out the raising or gluing operation.
Consequently, the receiving member as well as the raising head in the original position to return are required to be moved for different distances respectively until they reach the tiptoe portion depending on sizes of a shoe body to be processed. Particularly, in an equipment such as a shoe setting equipment wherein the starting time of movement of the raising or gluing head is the time for starting the raising or gluing operation, the different distance which the raising or gluing head is required to travel for, depending on sizes of the shoe body result in losses of operation time as well as deterioration of operation efficiency.
Another conventional shoe making machine, particularly the one relating to a device for properly controlling a shoe body setting equipment with respect to the raising or gluing equipment can be roughly classified in two types; one is the type to control the raising or gluing equipment by means of copying the outer marginal portion of the undersurface of a model of the shoe body to be processed, while the other is the type for controlling the raising or gluing equipment by travelling directly along the outer marginal portion of the shoe body to be processed. The former has such disadvantage as that the equipment becomes large in size since a model for the shoe body to be processed is required, while the latter has such disadvantages as that a comparatively large number of parts are required since many sensors are employed for detecting the configuration of the outer marginal portion, that its control is complicated, that a high degree of accuracy is unobtainable and that costs beccme comparatively high.
Other conventional shoe making machines which particularly relates to devices to raise the outer marginal portion of the under-surface of a shoe body are shown as typical examples in FIGS. 12 and 13.
In FIG. 12, a stationary shoe body a is set on a table. Two brushes 6, 6 are moved in the longitudinal direction of the shoe body a for brushing and raising the inside and the outside of the under-surface outer marginal portion c by means of electrically or mechanically detecting the external configuration of a model formed generally in the same configuration in its plan view to the bottom member (not shown) of the shoe body a.
In the above conventional equipment, in order to grind or brush the under-surface outer marginal portion c of, e.g., one of the pair of right and left shoe bodies a, a, two brushes having different revolving direction with respect to each other are moved in the longitudinal direction for grinding or brushing. Consequently, it has such disadvantages as that the raising of the two brushes 6, 6 are deformed due to one directional revolving. Furthermore, since it requires two brushes 6, 6 and two motors for driving the brushes, the structure thereof is complicated and two many parts are involved, thus resulting in high costs. In addition, there exists such technical problem as to control the revolving speeds of the two motors, respectively. Furthermore, since the under-surface outer marginal portion c of the shoe body a is unevenly formed in a horizontal plane; e.g., the arch portion d is of concave while the heel portion e and outside portion are of convex. Because of the foregoing, when the under-surface outer marginal portion c of the shoe body a is ground or brushed by using the conventional abrasive equipment, it occurs that the brushes 6, 6 contact the under-surface outer marginal portion c of the shoe body a too hard, or too weak, or otherwise a floating state of the brush is created. As a result, the under-surface outer marginal portion c is torn up, or otherwise there remains a portion left unbrushed. That is, the conventional equipment has such disadvantage as that the brushed portion lacks uniformity in its finish and that the yield of the product is poor.